> Hi,> Due to some unpredictable behavior in input data i end up with some> hundred partitions having more than 300MB size. Reading any sequence of data> from these partitions took about 5 seconds while reading from other> partitions (with less than 50MB sizes) took less than 10ms.> Since i can't change the data model in sake of a few problematic> partitions, Is there any tuning at Cassandra side that could boost up read> performance from the big partitions?> Thanks in advance>> Sent using Zoho Mail <https://www.zoho.com/mail/>>>> --

Column index size in the yaml (increase it to trade GC pressure for disk IO)

If you’re on anything other than 3.11.x, upgrade to 3.11.newest

-- Jeff Jirsa

> On May 19, 2018, at 8:42 PM, onmstester onmstester <[EMAIL PROTECTED]> wrote:> > Hi, > Due to some unpredictable behavior in input data i end up with some hundred partitions having more than 300MB size. Reading any sequence of data> from these partitions took about 5 seconds while reading from other partitions (with less than 50MB sizes) took less than 10ms.> Since i can't change the data model in sake of a few problematic partitions, Is there any tuning at Cassandra side that could boost up read performance from the big partitions?> Thanks in advance> > Sent using Zoho Mail> > >

I haven't try tracing, but i will and inform you!Sent using Zoho Mail---- On Sun, 20 May 2018 08:26:33 +0430 Jonathan Haddad <[EMAIL PROTECTED]> wrote ----What disks are you using? How many sstables are you hitting? Did you try tracing the request?

Should i run compaction after changing column_index_size_in_kb?Sent using Zoho Mail---- On Sun, 20 May 2018 15:06:57 +0430 onmstester onmstester <[EMAIL PROTECTED]> wrote ----I've increased column_index_size_in_kb to 512 and then 4096 : no change in response time, it even got worse.

Even increasing Key cache size and Row cache size did not help.

Sent using Zoho Mail---- On Sun, 20 May 2018 08:52:03 +0430 Jeff Jirsa <[EMAIL PROTECTED]> wrote ----Column index size in the yaml (increase it to trade GC pressure for disk IO)

If you’re on anything other than 3.11.x, upgrade to 3.11.newest

--

Jeff Jirsa

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